Leaving aside the fact that several are wideband units (so not to your taste Lynn 
), as I recall the inconsistencies with spiders is one reason Hartley introduced their double-layer VCs & magnetic suspension rather than a conventional spider, although what that did to the motor distortion & efficiency figures I don't know as I've never seen a proper data set on them. Over the past 18 moths or so, Markaudio have also started producing some single-suspension spiderless designs, except in their case the surround does all the work. Easier to produce those consistently than conventional spiders. Downside is production is harder due to the necessary tolerances, and maintaining stability is difficult, especially at higher excursions. Possible, but difficult.
), as I recall the inconsistencies with spiders is one reason Hartley introduced their double-layer VCs & magnetic suspension rather than a conventional spider, although what that did to the motor distortion & efficiency figures I don't know as I've never seen a proper data set on them. Over the past 18 moths or so, Markaudio have also started producing some single-suspension spiderless designs, except in their case the surround does all the work. Easier to produce those consistently than conventional spiders. Downside is production is harder due to the necessary tolerances, and maintaining stability is difficult, especially at higher excursions. Possible, but difficult.
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A merciful relief that they've introduced a round basket for these units as well as the squared off one, which probably put a bunch of people off. Thanks for the heads up Steve, hadn't noticed they'd brought these round basket versions out.
Re breakup at the top end of its BW, it looks fairly typical / adequte on this. A driver of that rated cone diameter is always going to be moving from oscillatory to resonant behaviour above c. 3.2KHz; it's just a question of how. Note from the impedance curve & frequency response it also has the cone-edge resonant mode at about 1.5KHz common to a lot of soft-cone drivers of this approximate size. That apart, SB have evidently followed the same practice they apply to most (most) of their range and not worried about completely damping out all the concentric modes.
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That is one of the things i do with my drivers.
Unless you count the singles that didn’t match to well (units being tested to see if they are worthwhile pursuing, i haven’t got that high a rejection rate.
I have a ton of data on the 2 main brands i sell, using a metric that groups various T/S, one brand is typically less than plus/minus 10%. The other more like 15% (across sets of 20 drivers). Because of changes in T/S with the “weather” it is not valid to compare batches mesured at different times.
dave
Scott speaks of the new Mark Audio drivers with mono-suspension. Mark 1st did the Alpair 5/Jordan J6T, a 3” driver with no spider and ferro-fluid. Euro law killed the use of ferro-fluid. Much more recently the Alpair 5.2 came out, an evolution of this driver with no ferro-fluid. It is a fantastic driver, no real bass (as would be expected) but an excellent midTweter, This was the test bed and there is now a 4” (A7ms) and a 7” (A11ms). I have only heard the latter so for (24 more of each awaiting treatment), and it is excellent.
dave
Dave at Planet10 has a valid approach ... widerange drivers, and the possibility of adding a supertweeter (such as a ribbon). If the crossover can be pushed up to 5~7 kHz, notches in the FR are much less audible than an octave lower. However ... an MTM going up that high is kind of dicey, with pretty severe lobing in the vertical plane, and a single widerange driver, as opposed to two in parallel, has 6 dB less headroom, and 3 dB less efficiency.
My feelings about peaks from the driver is they should be notched out, not just rolled off in the crossover. If the crossover lowpass function is relied on to get rid of the peak, the rise in IM distortion is still there, and the crossover phase in the peak/rolloff region is not well controlled. A combination of a notch filter plus rolloff, although more tedious to design and tune, can assure a smooth, phase-controlled rolloff. But even that is not necessarily the best sound ... my experience with notch filters is that they work well from a measurement perspective, including the time domain (if the peak is minimum-phase), but the speaker as a whole can sound lifeless and over-equalized. At other times, they sound fine with no apparent ill effects. Unfortunately, I have no way of knowing in advance if the combination of a complex crossover + driver with a single big peak is going to work well or not.
Tolerance of peaks seems to be very individual. I can't stand them myself, but speaker designers, as a group, tend to be intolerant of what they see (and hear) as design faults.
My feelings about peaks from the driver is they should be notched out, not just rolled off in the crossover. If the crossover lowpass function is relied on to get rid of the peak, the rise in IM distortion is still there, and the crossover phase in the peak/rolloff region is not well controlled. A combination of a notch filter plus rolloff, although more tedious to design and tune, can assure a smooth, phase-controlled rolloff. But even that is not necessarily the best sound ... my experience with notch filters is that they work well from a measurement perspective, including the time domain (if the peak is minimum-phase), but the speaker as a whole can sound lifeless and over-equalized. At other times, they sound fine with no apparent ill effects. Unfortunately, I have no way of knowing in advance if the combination of a complex crossover + driver with a single big peak is going to work well or not.
Tolerance of peaks seems to be very individual. I can't stand them myself, but speaker designers, as a group, tend to be intolerant of what they see (and hear) as design faults.
Usually we choose a FR with good top and add helper woofers. It has worked really well. In our big MTM (i think i posted a picture earlier of an example), the XO is at 250 Hz, C-C is less than a 1/4 wavelength at that frequency. Coupled with a 1st order XO (both drivers are happy with that) we essentially have coincident drivers with a phase coherent XO to give very good phase performance. Because of the C-C adding a tweeter of any sort is a bit of a crap shoot. Some of these FRs have a really good top.
We try to work those out at the source, making a filter unnecessary. Amp directly connected to the speaker (most times). We have a passive foe a couple of our WAW, but they are designed to be able to use a 1st order PLLXO when bi-amping. At these frequencies it can be cheaper going active than buying beer can size caps and equally humongus chokes.
Indeed. Many people are quite happy with peaks i could not live with, and even in some cases where there are still some residual issues even after i have tried my best.
dave
Might this not depend on the severity of the cone mode & how hard you stamp on it Lynn? As you mention, presumably some of the issue is that even if you flatten a resonant mode, the HD products lower down can still be present, & depending on their location / extent you can get just that sort of dulling effect. Possibly if the alternative approach of a high order filter is used at much over, say, 2KHz, the GD could also become increasingly audible, so we're back to the balancing act as usual.
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MTM is slightly confusing terminology under the circumstances, how about WWiW or WFW (WWW is probably even more confusing)
I don't see any reason for confusion. The drivers are arranged in an MTM configuration, ergo that's what it is. The nature of the midtweet is neither here nor there, or presumably examples with ribbon tweeters would be obliged to be called, say, MRTMs. Ditto for the crossover frequency, since there's no stipulation that the drivers are obliged to have an XO point within certain boundaries. What Dave shows is just variation on a very traditional 2-way, many of which crossed at 500Hz or lower.
Yes, I've said exactly that on many occasions on this forum and elsewhere for years. They're 2-way speakers.
I couldn't help thinking about the danish speakers from System Audio that have used Peerless drivers and MTM configuration for quite some years sometimes in a 2.5 way configuration with 2 or 4 drivers for baffle step. Recently they have been going to 3 way though. SA through time | SA
I google them and found these Vifas BTW. Hojttaler, Vifa, 4.5 F. – dba.dk – Kob og Salg af Nyt og Brugt
I google them and found these Vifas BTW. Hojttaler, Vifa, 4.5 F. – dba.dk – Kob og Salg af Nyt og Brugt
Lynn, thankyou for sharing your design of Ariel and ME2; no words or music can describe how much I enjoy the ME2.
I like to build a pair for my younger daughter as she is leaving home.
What should I use as a replacement (with the crossover design) for the no longer available Vifa driver to maintain the enjoyment of your original ME2 please ??
Cheers and much thanks,
King
I like to build a pair for my younger daughter as she is leaving home.
What should I use as a replacement (with the crossover design) for the no longer available Vifa driver to maintain the enjoyment of your original ME2 please ??
Cheers and much thanks,
King
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I'm not Lynn, but you've run into the basic problem with the Ariel & ME2. There are no direct replacements or substitutes for the Vifa P13. About the nearest regular production drivers are probably the Seas U16RCY/P, or Scan Speak 15W/8424G00 and 15W/8434G00. As noted, these are not drop-in equivalents though, so will require some crossover redesign.
Your too far away from me, I have 2 matched pairs bought just for the Ariels but never had the time to build them.
Not without doing a complete design from scratch I'm afraid. I'll see if I can come up with something using similar XO & voicing targets if I have time over the weekend, but it would only be theoretical using 3rd party data with simulated baffle effects added in, so we are emphatically not talking about something even remotely as refined as Lynn's original, just an approximation.
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Thankyou again sir.
I look forward to your suggestion, especially if you are using Ariel or ME2 now.
I really do enjoy the ME2, the only draw back is, my neighbor always thinks that I am a great piano player, and when I tell her the truth that I do not know how to play piano, she would always think that I am a liar.
I look forward to your suggestion, especially if you are using Ariel or ME2 now.
I really do enjoy the ME2, the only draw back is, my neighbor always thinks that I am a great piano player, and when I tell her the truth that I do not know how to play piano, she would always think that I am a liar.
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